alert

1 of 3

adjective

1
a
: watchful and prompt to meet danger or emergency
an alert guard
trying to stay alert to possible problems
b
: quick to perceive and act
mentally alert
2
: active, brisk
elicited an alert response
alertly adverb
alertness noun

alert

2 of 3

noun

1
: a state of careful watching and readiness especially for danger or opportunity
on 24-hour alert
2
a
: an alarm or other signal of danger
traffic alerts
They sounded the alert.
b
: an urgent notice
… an alert to parents … about new immunization requirements.Ann Schrader
3
: the period during which an alert is in effect

alert

3 of 3

verb

alerted; alerting; alerts

transitive verb

1
: to call (someone) to a state of readiness : warn
alerted the school board of a possible teachers' strike
alert the authorities
2
: to make (someone) aware of something
alerted the public to the dangers of pesticides
Phrases
on the alert
: looking for or expecting something (such as danger or an opportunity)
Drivers need to be on the alert for icy condition.
always on the alert for a good bargain
Choose the Right Synonym for alert

watchful, vigilant, wide-awake, alert mean being on the lookout especially for danger or opportunity.

watchful is the least explicit term.

the watchful eye of the department supervisor

vigilant suggests intense, unremitting, wary watchfulness.

eternally vigilant in the safeguarding of democracy

wide-awake applies to watchfulness for opportunities and developments more often than dangers.

wide-awake companies latched onto the new technology

alert stresses readiness or promptness in meeting danger or in seizing opportunity.

alert traders anticipated the stock market's slide

intelligent, clever, alert, quick-witted mean mentally keen or quick.

intelligent stresses success in coping with new situations and solving problems.

an intelligent person could assemble it fast

clever implies native ability or aptness and sometimes suggests a lack of more substantial qualities.

clever with words

alert stresses quickness in perceiving and understanding.

alert to new technology

quick-witted implies promptness in finding answers in debate or in devising expedients in moments of danger or challenge.

no match for his quick-witted opponent

Examples of alert in a Sentence

Adjective An alert guard stopped the robbers. He was tired and had trouble staying alert while he was driving. She wasn't mentally alert enough to answer the questions. An alert watchdog guarded the door. Noun They sounded an alert when enemy planes were approaching the city. Medical officials have put out an alert to hospitals to look out for the virus. The government has issued a terrorism alert. Verb Several neighbors alerted the authorities when they noticed strangers acting suspiciously. The governor alerted island residents that a hurricane was coming. The teacher alerted the students that tests would be given the next day.
Recent Examples on the Web
Adjective
Australia now has the world’s largest coastal drone-surveillance operation and is installing nonlethal traps, or drumlines, that alert authorities when a shark takes their bait. Michael E. Miller, Washington Post, 13 June 2024 The author renders the four-year-old Margaret’s inner life with sensitive complexity, depicting an alert child logic that defies adults’ view of her as slow and unfeeling. The New Yorker, 12 June 2024
Noun
The alert is for Wise, Denton, Collin, Hunt, Parker, Tarrant, Dallas, Rockwall, Kaufman, Hood, Johnson, Ellis and Henderson counties. Star-Telegram Bot, Fort Worth Star-Telegram, 13 June 2024 Meanwhile, operations on Cal State’s downtown campus will remain normal, the alert said. Melissa Alonso, CNN, 13 June 2024
Verb
The group has been pushing for the federal government to regulate sensors to be put in vehicles to alert drivers if someone is still inside. Michael Dorgan, Fox News, 17 June 2024 Some of these doctors are urging that a new name be given to the drug’s potential side effects to better alert healthcare professionals to its risks. Melody Petersen, Los Angeles Times, 17 June 2024 See all Example Sentences for alert 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'alert.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Adjective

borrowed from French alerte, going back to Middle French a l'herte "on guard, on the watch," borrowed from Italian all'erta, originally in the collocation stare all'erta "to be on the watch," literally, "to be on the height" (with erta "height, hill, steep ascent," noun derivative from feminine of erto, past participle of ergere "to raise, elevate," going back to Vulgar Latin *ērgere, by syncope from Latin ērigere) — more at erect entry 1

Note: The earliest citation for the word in the Oxford English Dictionary suggests direct borrowing from Italian, or at least recognition of an Italian source: "In this place the Prince [of Orange] finding his rutters [cavalry soldiers] alert, (as the Italians say) with aduise of his valiant brother, hee sent his Trumpets to D. d' Alua …." (Sir Roger Williams, The Actions of the Lowe Countries, London, 1618, p. 27).

Noun

noun derivative of alert entry 1 (or borrowed from French alerte, derivative of alerte, adjective)

Verb

verbal derivative of alert entry 1 or alert entry 2

First Known Use

Adjective

1618, in the meaning defined at sense 1a

Noun

1801, in the meaning defined at sense 1

Verb

circa 1868, in the meaning defined at sense 1

Time Traveler
The first known use of alert was in 1618

Dictionary Entries Near alert

Cite this Entry

“Alert.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/alert. Accessed 24 Jun. 2024.

Kids Definition

alert

1 of 3 adjective
1
a
: being watchful and ready to meet danger
b
: quick to understand and act
2
alertly adverb
alertness noun

alert

2 of 3 noun
1
: a signal of danger
2
: the period during which an alert is in effect

alert

3 of 3 verb
: to call to a state of readiness : warn

More from Merriam-Webster on alert

Last Updated: - Updated example sentences
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